The present invention relates to insect traps, and more particularly to devices for attracting, and trapping or killing mosquitoes and other biting insects.
Biting insects, such as mosquitoes and flies, can be an annoying, serious problem in man""s domain. They interfere with work and spoil hours of leisure time. Their attacks on farm animals can cause loss of weight and decreased milk production. Worldwide, mosquito-borne diseases kill more people than any other single factor. Mosquitoes can be carriers of malaria, yellow fever, and dengue fever in humans. In the United States, mosquitoes spread several types of encephalitis, including the West Nile virus. They also transmit heart worms to cats and dogs.
People are not the primary blood hosts for mosquitoes and biting insects, especially in temperate climates. The major mosquito pests in the southeastern United States seem to prefer the host-odor of small herbivorous (vegetarian) mammals, such as rabbits, or birds. Mosquitoes that carry encephalitis seem to prefer avian (bird) blood hosts. These mosquitoes bite people when they get the chance, but they are better at tracking the scent of animals that are most abundant in their habitat.
Mosquitoes locate blood hosts by scent, sight and heat. From 100 feet away (30 meters) mosquitoes can smell a potential blood host""s scent, especially the carbon dioxide (CO2) the blood host exhales. Similarly, biting flies can smell their prey from 300 feet (100 meters) away. Because CO2 is present in the atmosphere (plants take in CO2 and give off oxygen), mosquitoes respond to higher-than-normal concentrations, especially when the CO2 is mixed with host-odor. They follow a blood host""s scent upwind, and can see a target at a distance of about 30 feet (10 meters).
People have tried a number of different methods to rid themselves of mosquitoes and other biting insects. One method that is often utilized is spraying or applying chemical insecticides. Although many chemicals work well to kill or repel mosquitoes, the chemicals often have a deleterious effect on the environment, including, but not limited to, killing beneficial insects. In addition, chemical insecticides are effective only for a limited amount of time, and thus must be continuously sprayed. Moreover, many types of mosquitoes and biting insects are capable of developing resistance to the chemical pesticides in a few generations (which may only take a few months for mosquitoes), and in the long run, that adaptation makes the species stronger.
Another method used to combat mosquitoes is bug zappers. In general, a bug zapper includes a fluorescent light source surrounded by an electrified grid. The theory behind these devices is that the mosquitoes are attracted to the light, and, upon flying to the light, will be electrocuted by the grid. In actuality, however, the bug zappers kill beneficial insects, and attract mosquitoes but don""t kill them in significant numbers. Thus, individuals that are located near a bug zapper may actually experience more mosquito bites than those that are not.
Citronella candles and smoking coils are often used to repel mosquitoes and other insects. However, research has shown that, in general, an individual must stand within the smoky plume of the citronella to be protected. This, of course, is not desirable. Moreover, even when standing in the plume, citronella is only partly effective in reducing the probability of a mosquito bite. Encouraging natural predation of insects by setting up bird or bat houses in the backyard has also been unsuccessful in reducing local mosquito populations.
Recently, significant research and effort have been expended to develop devices that attract and trap or kill mosquitoes. In general, these devices attempt to replicate the mosquito-attracting attributes of a typical blood host, such as a rabbit or a bird. The devices may include, for example, a source of carbon dioxide, a source of octenol (an alcohol that is given off by mammalian blood hosts), and/or a heat source.
One such device is sold under the trademark xe2x80x9cMOSQUITO MAGNETxe2x80x9d and is described in U.S. Pat. No. 6,145,243 to Wigton et al. The MOSQUITO MAGNET apparatus is an insect trapping device that generates its own insect attractants of carbon dioxide (CO2), heat, and water vapor through catalytic conversion of a hydrocarbon fuel in a combustion chamber. The hot insect attractants generated in the combustion chamber are diluted and cooled to a temperature above ambient temperature and below about 115 degrees Fahrenheit (F.) by mixing with air, and the mixture is exhausted downward through an exhaust tube. A counterflow of outside air is drawn into the trap though a suction tube that concentrically surrounds the exhaust tube. Biting insects are sucked into the suction tube and are captured in a porous, disposable bag connected to the other end of the suction tube. Additional chemical attractants may be used with the device to make the trap even more effective.
Although the MOSQUITO MAGNET device works well for its intended purpose, it is a very bulky device which cannot reasonably be taken to remote locations such as for camping, boating, or the like. These recreational activities are among the primary arenas where individuals may encounter mosquitoes and other biting insects. Moreover, due to its high suggested retail price ($700 to $1300, depending upon the model), it is far out of reach of the ordinary consumer. Thus, few people would actually purchase the MOSQUITO MAGNET, even if they have a pressing need for mosquito control.
Another example of an apparatus for attracting and destroying insects is disclosed in U.S. Pat. No. 6,055,766, and is sold under the trademark DRAGONFLY. The DRAGONFLY apparatus generally includes a source of carbon dioxide, a source of octenol, a device for emitting the carbon dioxide proximate the source of octenol to create a mixture of the carbon dioxide and octenol, a heating element, and an electrified grid. Insects are initially attracted to the apparatus by the odor associated with the mixture of carbon dioxide and octenol. As the insects fly closer to the apparatus, they are further attracted to the visual properties of the apparatus and then, at close range, they are attracted to the heat emitted by the heating element. In an attempt to fly closer to the heating element, the insects are intercepted by the electrified grid and destroyed.
Although the DRAGONFLY apparatus works well for attracting and capturing insects, its heating source and electrical grid are reliant upon an AC power supply, and thus the portability of the DRAGONFLY apparatus is limited to locations that can be reached by an electrical extension cord. This feature limits the use of the DRAGONFLY apparatus mostly to home use, and even limits the locations where it may be located around a home. Moreover, as with the MOSQUITO MAGNET device, the DRAGONFLY apparatus, at a suggested retail price of approximately $700, is priced out of the price range of the ordinary consumer.
There exists a need for a mosquito attractor and trap that is portable, so that it may be easily moved to a desired location, or used in outdoor recreation, such as camping or boating. Preferably, the mosquito trap may be produced and sold relatively inexpensively, so that it may be purchased by a typical consumer.
The present invention is directed to a mosquito and biting insect attracting apparatus that is both portable and inexpensive to manufacture. In accordance with one aspect of the present invention, the mosquito and biting insect attracting apparatus includes a heat element (a thermal lure), a source of carbon dioxide (CO2), and a source of a chemical biting insect attractant, such as octenol. The thermal lure, the chemical biting insect attractant, and the CO2 simulate a small animal, thus attracting mosquitoes and other biting insects to the mosquito and biting insect attracting apparatus. A mechanism may be provided for trapping or killing the attracted mosquitoes, such as a sticky adhesive tray or an electronic grid.
In accordance with an aspect of the present invention, the heat for the thermal lure and the source of CO2 are provided by a propane flame. The propane is supplied, for example, by a small propane tank that is attached to the mosquito and biting insect attracting apparatus, and that is mounted, for example, in a bottom portion of the mosquito and biting insect attracting apparatus. The propane tank is connected to a burner that, in operation, produces combustion. The burning propane produced by the flame is the source of the CO2. If desired, the propane tank may be mounted in a recess in the mosquito and biting insect attracting apparatus. Alternatively, the propane tank may be mounted under or beside the mosquito and biting insect attracting apparatus, and the apparatus may include removable or foldable legs for support. Removing or folding the legs compacts the mosquito and biting insect attracting apparatus for easier transport.
The thermal lure includes a structure that surrounds the burner and that is heated by the burner to a temperature that is similar to that of a small animal, such as 95 to 115 degrees Fahrenheit. The structure includes a series of baffles and conduction elements that permit the structure to have a substantially constant heat signature, which is desirable for attracting mosquitoes and other biting insects.
In accordance with one aspect of the present invention, the thermal lure includes three concentric cylinders, each made of aluminum or another highly thermally conductive material. The innermost cylinder surrounds the flame of the burner, and heat is transferred to the outermost cylinder from the innermost cylinder by thermally-conductive connector arms. In accordance with a further aspect of the present invention, the connector arms extend to the bottom of the outer cylinder, so that heat may rise to the top of the outer cylinder and the outer surface of the outer cylinder maintains a substantially constant temperature.
The central cylinder and the baffles work together to dissipate the heat of the exhaust of the flame, by moving some of the exhaust sideways out of the thermal lure, so that not all exhaust exits the same location, thus avoiding a hot spot in the thermal lure. In addition, the baffles and central cylinder help to mix the exhaust with ambient air, increasing heat dissipation and further reducing the possibility of a hot spot being formed on the outermost cylinder by the exhaust or convection.
An adjustment mechanism may be provided to adjust the height of the flame. In this manner, the flame height may be adjusted to account for ambient temperature, or to provide a thermal footprint that is appropriate for a location or weather condition. If desired, settings may be provided for particular weather conditions, such as temperatures, so that a user may set the flame to the appropriate level for a given weather condition.
The source of the chemical biting insect attractor may be, for example, a strip of octenol. In accordance with one aspect of the present invention, an octenol strip is mounted in a holder on the side of the thermal lure, whereby the heat of the thermal lure may be used to activate the octenol in the strip. If desired, the octenol strip may be provided in a disposable container, such as a tray, so that it may be easily replaced when the octenol is evaporated.
The trapping or killing mechanism may be sticky adhesive, provided, for example, on one or two trays that are situated around the thermal lure. In accordance with one aspect of the present invention, the adhesive may be provided to a consumer on a pair of trays. Each of the trays includes a pair of fold lines so that the trays may be folded into trifold, half-hexagon shapes. A backing is removed from the adhesive material, and the two halves are placed on opposite sides of the thermal lure with the adhesive facing outward. The trays may include guides along their outer edges that fit onto rails within the mosquito and biting insect attracting apparatus, providing easy removal of a tray filled with biting insects and easy replacement of a new tray.
Preferably, the mosquito and biting insect attracting apparatus requires a minimal flame for operation. In this manner, a small propane fuel tank, such as the 16.4 ounce COLEMAN propane fuel tank manufactured and supplied by The Coleman Company, Inc., the assignee of the present invention, may provide enough fuel for the mosquito and biting insect attracting apparatus to operate for approximately 50 hours, which is equal to running the device approximately 3 hours per night (prime mosquito time) for 2 weeks. A 20 pound bottle of propane may be connected to the mosquito and biting insect attracting apparatus to allow operation for over 1000 hours. If desired, the octenol strip may be sized and arranged so that the octenol on the trays evaporates in approximately the same amount of time as normal use of the small propane tank over two weeks. Thus, maintenance of the mosquito and biting insect attracting apparatus would require only that the tank be replaced or refilled, and that the octenol tray be replaced once every two weeks. Occasional replacement of the adhesive trays may also be needed, especially where the trays are full of mosquitoes or other biting insects, or when the trays become dirty.
A removable or hinged top may be provided on the top of the mosquito and biting insect attracting apparatus for accessing the octenol tray and the adhesive trays. In this manner, easy access may be had to the trays for maintenance or replacement. In addition, the top provides some protection for the adhesive trays from dirt and other foreign matter.
Other advantages will become apparent from the following detailed description when taken in conjunction with the drawings, in which: